Overhead trolley system and frog



Jan. 22, 1946. w. J. LEWIS' 2,393,388

OVERHEAD TROLLEY SYSTEM AND FROG Filed Nov. 25, 1945 v 3nnentor WARRENJ. LEWIS Gttorneg Patented Jan. 22,1946

I UNITED STATES PATENT OFFICE 2,39s,sss- OVERHEAD TROLLEY SYSTEM ANDFROG Warren J Lewis, Mansfield, Ohio, assignor to The A Ohio BrassCompany, Mansfield, Ohio, a. corporation of New Jersey 5, 1943, SerialNo. 511,743

11 Claims. (o1. 191-38) This invention is directed to an overheadtrolley switching system and frog therefor in their moreparticular'aspects concerns a system and a frog j having very rapid anddependable oper ating characteristics.

One object of this invention is to provide a trolley frog having acontrol circuit for a solenoid operated tongue shifting mechanism thatis extremely sensitive, positive and unfailing'in operation anddepending for its actuation upon the longitudinal position of thecurrent collectors relative to each other along the-trolley wire.-

Another object of'the invention is to provide a trolley frog in whichthe energization' of the shifting mechanism is made continuous 'ateachoperation of the frog for a predetermined time depending upon the lengthof the contactors and the vehicle speed.

A still further object of the invention is to provide a trolley frog inwhich the tongue shifting mechanism is provided with relay means tocontrol the length of time of energization of the operating coilsthereof and having means to produce a brief current surge through theoperating coil for the relay in order to increase the speed of and theeffective time of energization of the relay coil. 7

Another object of the invention is to provide a trolley froghaving a'tongueshifting mechanism'including means to apply to-the operating coil1 or coils, upon energization thereof, an instantaneous surge 'ofcurrent of brief duration and of sufiicient magnitude wherebyinstantaneous operation'of the tongue shifting mechanismisefiected. s r

-A still further object of the inventionis to provide a condensercircuit in a trolley frog mechanism to increase thespeed of operation'of the tongue shifting coils. 1 V v Another object of the invention is lto provide a. trolley frog having a control circuit for thetonguezoperating mechanism and having a rel- ,atively'lowinitialresistance tokproduce a high instantaneouscurrent surge inthe controlcircuit and which resistance increases rapidly after energization toprovide alower holding current.

v.Other and still'further objects .of the invention'will. occur tothoseskilled in' thearts to which. this invention pertains as the descriptionproceeds which taken .in connection with the accompanying drawings setsforth a preferred embodiment and a selected modification thereof butsuch disclosures are not tobe construed as a1im-' itation ofthe.invention which is limited only; by

theappended claimsand anyand all modiflcas tions, alterations andvariations of structure coming within the spirit and scope thereof aredeemed to be included herein. V

In the drawing:

'Fig; 1 shows a preferred embodiment of thetrolley frog operatingmechanism,

Fig. 2 shows a modified control circuit for the mechanism of Fig. 1. p

Prior art frog mechanisms of the'automatic type have certain inherentfactors that affect their speed of operation, viz., the time the tongueoperating circuit'is energized by the vehicle and the magneticcharacteristics of the circuit. The second factor is improvable by theuse of more powerful and even overloaded coils. There are dangers inthis expedient, with frequent coil burnouts which may be caused by thevehicle stopping with its current collectors on the contactors ortraversing them to slowly. With suitable pre cautions this expedient isfeasible up to a certain point in solenoid construction but when theturns are increased there is also an increase in inductance whichhas theadverse tendency to retard or slow down coil action and the operation ofthe tongue mechanism. I

In prior art devices the time factor or length of time the energizingcircuit is closed varies inversely as the speed of th vehicle anddirectly as'the effective length of the trolley contactors;

The speed of travel ofthe vehicle maybe increased over. that allowableby present-day devices by theemployment of relays. One such organizationis set forth in applicants co-pending application S. N. 437,556, filedApril 3, 1942. The instant disclosure is an improvement over my priordisclosure and-sets forth a mode of operation that allows a more rapidvehicle speed through the frog and employs a control circuit that ismore sensitive and which is absolutely reliable in its operation as longas there are no mechanical impediments hindering the operation of thetongue shifting mechanism.

priate fittings.

The objects and advantages enumerated above are achieved in a devicegenerally disclosed in Fig. 1 in which I and 2 are pan elements to oneend of which approach trolley wires 3 and 4. of opposite polarity aresecured by means of appropriate fittin s and at the other end turnofftrolley wires 5 and 6 and straight through trolley wires 1 and 8. aresecured by means of appro- Pivotally mounted on each pan element I and 2are tongue'elements 9 and In, preferably of the double runner variety.'Pins I I and [2 provide the pivoting connectionbetween tongue and panelements and pivot with the tongue. Proper spacing between the panelements is maintained by means of insulator elements l3 and I4 eachpivotally connected to the respective pan elements. The foregoing isconventional structure common to a, large variety of trolley frogs.

Each of the pin elements I I and i2 has secured thereto at its one endlever arms 55 and is respectively which aregnovable with the pins l andI2 and with the attached tongue. By moving or rotating the levers I 5and It the pins H and I2 will rotate and shift the runners of thetongues to the straight through or curve position to there.- by line uptrolley wires 3 and 4 with either of Wire pairs 5 and 6 or 7 and 8.

The spring pressed detents H and 18 secured to spring elements l9 and 20preferably are anchored to the frog pans l a d 2 and maintain the leversl5 and [6 in either selected adjusted position. The faces of the detentsare slanted e c emi t-e91 s sh s and en age with one f e a es on the o ned end. eiievers. is .1.5- A tilting or lifting of the detents il' an13. by the levers I5 and 16 respectively allows-levers l5 and 1.3 topass underneath then from one position to the other.

P ve e l e ured n the levers and s a plunger elements 2| and 22 .of thecoils. 2 3; and 2. These s i a e, hewn a of h s n le se inc var ety nrot t the ass iated nsil and 1e 2; e em n s 1 ,6 "1 one di e iiee The.se l p tab y selec d. ireel s by m ans s e iidlle 2s. and; 2? betoperate if connected parallel. Ifhe com. lus -Pre nd 2. a e di ecteenneet d t t e ta t devis 2: id s r 'esreetic lr is the er s l is eident the eisr tliatwhen i! eneii are l a hengagemen s i ef v se 2.8 nd;2.9 I. tie, the ils wi l e se isle. arms and liens t. .l 'resaeei e insand t ached teaches, the. ea ue re set. e tra ght: 2 3 3913511: ope aion the. s ii in by the, 9 gized will be to curve or turnoff L Q contacd vices 3 an 2? are. 12:6. s y; s ace h pans, I; and; Z: on encroach sde thereof.

Her sein cond tions of: operation. the above ircuit ma be ad a e for. nsance t as of a l w v hic e. sp ed.- Whsn, the vehicle on whichcollectors :36 and .31: are a ri d t avels athi h rate o sliced e tonues 9 [u narnot beshifted in time to properly; guide. the col.- lectors.

The relay 3.12 and circuit. shown prcvidesrneans for the completion ofthe Sh fting of; the tongue elements in ample time thereby:-accommodating a rapidly traveling vehicle. Bhe relay circuit comes intoplay assoon as the. collectors 3i]: and: 3|v engage contact devices 28and 29. respectively. As soon as collectors 38 and Si are in engagementwith both contact devices28. and 23? thus energizing the same, relay 32:is energized: and closed as long as collector 31 engages contact device29 by'me'ansof the conductor 33; connected to resistance unit 34 in turndirectly. connected to the coil 3'5 ofrelay 32, and thenceby conductor36 connected to the contact. devicel 28.

With frog constructionas of today, one of. the collection devices on a.vehicle traveling at higher than normal speeds through the frog wouldpass at least oneof the contact'devices beforethe'operating coils-becomeenergized. or sufiiciently energizedto effect a shifting ofthe tongues.How-v ever, with the use of relay 32, the collector 30 may pass thecontactor 28 but the tongue operating coils will remain energized aslong as relay 32 remains closed which is until collector 3i has passedcontact device 29 since the conductors 35 and 3! are indirectlyconnected to the trolley wire 4, relay contact element 38 and conductor39 which is directly connected to trolley wire 3. As long aslcp'llector3| is incn agement with contact device 29 after collector 30 has engagedcontact device 28, the relay will be energized thereby providing alonger period of energization of coils 24 than in frogs of today.

By constructing the tongue shifting mechanism and the relay pants 38with low inertia plungers, just the briefest "period of contact betweenthe collectors and the contact devices 28 and 29 will bring relay 3;into play and assist in making certain the energization and the shiftingof tongues 3- and It]. It is evident then, that the l gth of onta de ice29, a d sneed of t 1e ehie edeternime the leng o th timecoils 2 3. a 24are ene gized.

Me ly as a e mpl and notes alimitation the coil 35 may be soconstructedas to permit a om what g at r current fl w thcret reus than sa e i r prolonged enereiaa ion if an-- neoted directly to, th contactdevices. This greater current would bring the coil up to full; en rgizaion qui l unon el s. ts c rcui an effect a. auiek operat on of therelay.- --'I.his creat r ur nt is duced to a sate value for prolonged.rs t on s hen. t e ve i le stops. with the ollectors on the conta tdevices the of resistance 34.

s r s stance ,34 will. protect the co l 3.5v f om damage due tooverheating under continued errergization but under certain operatingconditions. th rel y sw tch i l not respond,- cuclr enou h.

y o ne t n the eon-dense 9 c oss t e t ri sls. the esi t nce 34, the; eec i he: M

a parallel circuitlof low resistance to the resists nce .34 fo a verybrief-P r d. of time attir instant the coil n r izing circu t s c eherebx ausin a g eater urr nt. rcurr nt ur etq fle tlirqueh he eqilor ninstant ln allowed by the resistance 34, thereby bringing the coi eneresation u to ill value instant As, soon as the condens r has. funct oned.t resistan e fun tions o educe the curren flow to. its predeterminedsate va ue. but suili ient to mainta n the ener ization 00113415.

After the, passag of the: collectors. 3.0 and. 3!; past the tongues, rset mecha isms .1- and; 42; respectively connected to plungersgi, and2!. hr means of lmkages 43 and &4. schematically shown, restore. the,tongues 8- am. Hi;- totheir 10.1? may or straight tl-irou h position.when en aged by the passing current collectors.

When it. isdesiredto.continue.strai htthroug the frog mechanisms there,will, of: course, be no tongue shifting; necessary; In this-eventitis dosirable thatneither the coil 35.norrelay. operate. ing circuit be closedand. therefore collector 30.. will havebeen disengaged from contactdevice 23; before collector 3|. engagesrcontact; device 29. In order toaccomplish this. the. distanceX mustbe as long orlonger than. the.length ofrcollector 30.

Duringoperation when both. contact devices 28, 29: are engaargiedbycollectors. 30, 31-. respectively at the same time, relay. 32 isvenergized as previously explained, and. is maintained energized: as longas:col1ector3 l and contact devicelfii remain in engagement. Theenergizing circuit for coils 23- and 2-4, after the brief initialengagement ofbothv collectors with both contactors, will now comprisecollector 3|, contactor. device 29, conductor 25, coil 24, conductor 26,coil 23; conductor 21, conductors, and 31, relay contact element 38 and.conductor 39 to trolley wire 3. The full line positions 30 and 3| ofthe collector indicate their relative position during a turning of thevehicle and the full line position of collector 30 and the dotted line3| or collector 3| in transversely disposed alignmentindicates thestraight through position of the collectors 30 and 3 I".- Nocoiloperation will be and is necessary for straight through operation.

-- .The .modified disclosure shown in Fig. 2 is identicalzin every,respect to that of Fig. 1 except thata tungsten lamp 45 has replaced theresistance unit 34. The resistance characteristic of thetungstenfilament is employed here to secure a high 'speed'operation ofrelay 32. It is known that the cold resistance of a tungsten filamentedlamp is very low and its hot resistance almost ten times greater thanthecold resistance. Bycarrying out thesame principle in designing thecoil as-in the case of Fig. 1 and upon closingthe coil energizingcircuitv which includes the filament 45 .there is a momentarycurrentsurge through the relay .32. 'This surge is depended upontoactuatesrelay 32 very rapidly which'is materially reduced almostinstantly upon the full heating of the-lamp. filament. A condenser40'asshown in dotted. lines may be employable when ultra high speed isdesired butis not so important as in Fig. l. The .operation of the relay32 and the coil circuits for the tongue shifting mechanism is identicalwith that described above with referenceto Fig;.1. I

1 As an exampleand not as a limitation, in case of: Fig. 2,; theresistance of the coil 35 may be 1,000. ohms which on a 600 volt circuitwill permit a. flower current of .6 ampere which would be 21 'would beomitted in case of the use of the parts 50 and 5|. The use of elements50 and 5| is' optional as the system. will operate without them. Alsothe system will operate if the elements 50 and BI are used butthe relay32, resistance 34 and condenser 40 omitted as the function and operationof the; two controls described are entlrely independent.

The relay 32 and members 34 and 40, also the members 50 and 5| may beused in conjunction with a frog employing two operating coils per pan vasshown in US. Patent 2,264,839.

destructive to the coil in a very short time. The

cold value of the resistance may be 2,000 ohms which with theresistanceof the coils amounts to 3,000-ohms and permits a surge of current of .2ampere which would give a rapid energizationof the coil but would stillbe too great for a continued flow beyond a minute or two. But, the valueof the resistance 45 will immediately increase to possibly 20,000 ohms,thus reducing the currentlfiow to .028 ampere, a safe value. In the caseof Fig. 1 the resistances 34 and are of Nichrome or similar material,hence the change from cold to hot resistance is slow and is very smallcompared to the element .45 as described, therefore the use ofcondensers is advisable.

. The several disclosures show a frog pan organization in which thetongues are normally set for straight through operation. It is clearthat by proper arrangement of the contact devices 28 and 29 and resetlevers 4| and 42, this same system of operation can be employed on afrog pen in which the tongueis normally set to curve and in which thetongue will be shifted to its straight through position with a reset tocurve afterthe collector passes the tongue. V V

, In Fig.1 is shown in dotted lines, means for applying the principleinvolved in the use of resistance 34 and condenser 40 whereby theoperation of the tongue shifting mechanism may be speeded up. Here isshown a resistance 50 in series relation with the conductor 21 and acondenser 5| connected in parallel with the resistance w5|ltherebyshorting the resistance for an instant and permittinga current surgethrough the coils 22 and 23. The portion 52 of the conductor i Contactdevice 28 may be shorter than contact device29 thereby reducing weightand cost but the use of the relay switch in such case is advisable as itinsures operation of the tongues.

Frogs have been proposed in which a resistance Wasconnected in serieswith the operating coils and normally short-circuited by a switch whichautomatically opened and closed with and by the movements of thetongues, but in my invention the resistance and condenserare-connectedpermanently in circuit, the arrangement is suchas toavoidthe use of any moving parts to control the current flow through thecoils, as the condenser automatically controls the functioning of theresistance. The resistance in assures full discharge of the condenserbetween operationscf the-frog.

The relative resistance of the various coils to their respectiveresistances and the cooperation of the condenser may vary greatly tomeetdifferent operating requirements, therefore it" 'is quite impossibleto give values therefor which will be applicable in general.

I claim: r

1. In a switching system for a pair of current collectors mounted on avehicle, in combination, a pair of main'trolley' wires of oppositepolarity and a branch wire for'each main wire, a trolley frog at theintersection of each main and branch wire and provided with a movabletongue to guide a current collector on the vehicle either along the mainwire or onto the'branch wire, a contact device associated with eachtrolley wire on the approach side of the frog to be electricallyconnect'ed'to their respective wires by passing current collectors,electrically operated mechanism including coils to shift the tongues,conductors connecting the coils to said contact devices, a relayincluding an operating coil and a contact element, conductors connectingthe relaycoil to the contactdevices, the relay coil and the coils of theelectric'al mechanism being energized when the contact devices aresimultaneously engaged by their respective current collectors andcircuit means closed by the contact element when the relay coil isenergized thereby connecting one of the contact devices to itsrespective trolley wire.

2. A switching system according to claim 1' in which there is includedin combination with the relay coil, control means to momentarily pass acurrent through the relay coil at the instant of its energizationsufficient to assure the rapid closing 'of the relay contact element andthen reduce. the current to 'a value suflicient to maintain the relaycoil energized and the frog tongues in 'theirproper guiding positionwithout danger of the coil overheating.

13. A switching system according to claim 1 in V parallel with thecondenser.

closing :of: the relay contact-element and; :then automatically reducethe current to a 'valuezsuf' ficient towmaintain thereiay :coilenergized-a d the frog: tongues vinutheir properguidingv positionwithout danger. Ofuthe relay 1 coil overheatihggsthta said control:meanscomprising; resistan'ceiomeans included incseries insaid:conductor means; and condenser means connected in shuntwith'the-resistance means. Y I

v 4-. A-trolleytransportation system comprising; a ofinaintrolleywiresrofopposite polarity and a branch wire fromaeach main wirea-tmlloyfrog; at. the intersection of each branch and-main Wire; a pair ofcurrent; collectors mounted on an electrically operated vehicle, movabletongues associated with the frogs to. guidethe collectors along. themain wires oronto the branch'wires, a contact device associated witheach main wire, thecontact. devices energizable when engaged by thecurrent collectors, electrically operated mechanismincluding anoperating coil formoving each tongue, conductors connecting saidoperating. coils to both contact devices, the operating coilsbeing-energizedwhen both contact devices are energized by the currentcollectors at the same-time, and-means to continue the-energization ofthe coils after one current collector has passed its contact device andthe other collector still in engagement with its contact device, thesaid means comprising-arelay including a contact element and anoperating coil, conductor. meansconnecting the" relay coil to thecontact devices whereby; the relay coil. will be energized at the sametime bothcontact devices are. energized, and circuit meanssoconnected-to said conductor means'and to one trolley wire and to therelay coil and closed by the cQntactelement when therelay. coil isenergized-that the mechanism coils and'the relay coil will remainenergized as long asthe said other collector i still in engagement withits contactdevice.

In .anoverhead switching system for a pair of: current. collectorsmounted. on a vehicle, in combination, apair: of main trolley-wires ofopposite polarity and abranch wire. from each main Wif'firanda a trolleyfrog. at the intersection of each mainandhraneh Wire, each frogiprovidedwith arncyablev tongue to guide saidcurrentcollectoz seither along the.main wires or on to-the branch wires, acontact device associated witheach main wire-andenergized from their respective--trol-ley Wires whenengaged by theocurrent collectors; electrically operated mechanismassociated with the frogs to shift the' tongues and conductorsconnectingthe mechanism tothe contact devices; a relayincluding anoperating coiland a circuitclosing contact element, con-'- duntor' means connectingthe relay coil to the contact devices. whereby the said relay coil andthe-:said. mechanismwill be energized-while the current collectors arein engagement with both contact devices at the same time; and circuitmeans closed by the contact element when the relay. coil is energizedthereby connectingi the electricallyoperated mechanism and relay: coilto both trolleywires when onlyone contactdevice-is energized by itsengagement with its current collector.

6. A switching system according to claim 5 in which there is includedin. series with. the relay coil and the conductor means, resistancemeans toreduce a-sustained current through the relay coiltc a safevalue, and means associated with the resistance means tomomentarilynullify, its effect at theinstant of the energiz'ation of the aseaeesrelay coil toaassurertherapid closing ofthe relay contactelement.

Ia-A switching .systemrcomprising, a; pair of main: trolley wires ofopposite polarity and a branch wire from each: main wire,-a trolley frogatseachintersection of a branch and main wire; each: "frog. providedwith :a; movable tongue to guide "a; current collector mounted onamoving vehiclethrough the-frog, acon'tact device hinted; with eachtrolley wire*to' be" electrically connected to their respective wires bythe passing current collectors, electrically; operated mechanismincludin coils to shift the ton'gues, a relay including an operating.coil and a'contact element; conductor means connecting the: mechacoilsand the relay coil to thecontact devices; whereby the said coils willbeenergized whim-Lathe contact-devices: are- 'both in engagement withtheir respective current collectors: at thersame. time; .circuit' means:closed by: the contact-l elementvwhen' the. relay 'coil is energizedthereby connecti-ng one "or? said contact devices mite-"respectivetrolley Wire: and control means associated 'with the conductor meanstomomentar-fly pass a current through the coils at the in= stanti bothcontent devices are energized to sure'the. full and rapid energizationof the coils and? .thexrapid-and positive: closing. of the contactze'lement' and operation of thetongues" and then reducing; the:current through the coils to a valueisufilcient to maintain the: coilsenergized and the: tongues in their: proper guiding position withoutdanger: oi the coils overheating.

8: 311128; switching i system for aipair 01' current collectors. mountedon ia vehicle'; in combination, a pair of main trolley wires ofoppositdlwolarity and a lbranchzwireifor each; mainwire', a; trolleyfrogfat the intersection ofeach main and branch wlre-sandprovidedwith'amovable tongue to guide a: current collector-on the vehicleseitheralong the maln wire' orronto the branch wire, a contact deviceassociatedxwith each trolley. 'wire" on the: approach: 1 side or. thefrog; to be electrically connected to their respective wires bypassingcurrent I collectors; electrically" operated mechanism including coilsto shift :the" tongues; con (motors:v connectingth'e' coiis to sai'acontact de= vi'ces' a relays'includine an; operatingmoil and a contactelement; conductors connecting the relay coilito the: contactdeviceswhereby the relay coil and: -the coils of the-electricalmechanism'will be energized when the contact devices are simultancoustyengaged by their" respective current col rectors; circuit mea-risclosed' by the contact element when r the i relay: coil is'en'eri-iiz'edthereby connecting one i of the contact devices. toitsrespeetivetrolley wire and control means connected in series' with oneof said conductor-std momen tarily pass-a current through the-coi1 orcoils contcoiled -by the conductor at '-the instant of the-ehei'gizationthereof to essnre the rapid and positive ener ize-lawn of the:coiloncoilsans then reduce the current te a value suiiieient'toinaintairr the energization of the coil or coils without danger ofoverheating,

9. Atrolleyrrog -for=an-'-overheadtwo Wire'syS- tem' comprising a; pairor trolleyfro-gs; each flog provided withhmeans' to receive a main? anda branch wireand" eachffog "having a movable tongue" tdguide' a' passingcurrent collector through the frog; insulating meanstomaintain the frogsin spaced" relation thereby forming a uriitalrydcvlcet eiectr c nyoperated" mechanism including coils "to" shift the-i tongues; the coilsadapted to be connected to contact devices asby the current collectorsrespectively, control means including an operating coil associated withthe trolley frogs adapted to be connected to said contact deviceswhereby the mechanism coils and the coil for the control means will beenergized when both contact devices are engaged respectively at the sametime by the current collectors, the said control means comprising acontact adapted to connect said coils to one trolley wire whereby theenergization of the mechanism coils will be maintained. as long as thecontact device associated with the other of said trolley wires isenergized after both contact devices have been energized. V

10. A switch system according to claim 4 in which there is included incombination therewith resistance means to limit a sustained currentthrough the said coils to a safe value and means associated with theresistance means to momentarily by-pass the resistance to assure therapid energization of the coils and the closing of the the coil of therelay to reduce sustained currents through the coils to a safe value andmeans associated with the resistance to momentarily by-pass theresistance at the instant bothcollectors are in engagement at the sametime with their respective contact devices to assure the rapid andsufficient energization of the coils. WARREN J. LEWIS.

